I could expostulate you could expostulate he could expostulate we could expostulate you could expostulate they could expostulate
V-ing form
I could be expostulating you could be expostulating he could be expostulating we could be expostulating you could be expostulating they could be expostulating
Perfect
I could have expostulated you could have expostulated he could have expostulated we could have expostulated you could have expostulated they could have expostulated
V-ing perfect
I could have been expostulating you could have been expostulating he could have been expostulating we could have been expostulating you could have been expostulating they could have been expostulating
Negation
Simple form
I couldn't expostulate you couldn't expostulate he couldn't expostulate we couldn't expostulate you couldn't expostulate they couldn't expostulate
V-ing form
I couldn't be expostulating you couldn't be expostulating he couldn't be expostulating we couldn't be expostulating you couldn't be expostulating they couldn't be expostulating
Perfect
I couldn't have expostulated you couldn't have expostulated he couldn't have expostulated we couldn't have expostulated you couldn't have expostulated they couldn't have expostulated
V-ing perfect
I couldn't have been expostulating you couldn't have been expostulating he couldn't have been expostulating we couldn't have been expostulating you couldn't have been expostulating they couldn't have been expostulating
Interrogative form
Simple form
could I expostulate? could you expostulate? could he expostulate? could we expostulate? could you expostulate? could they expostulate?
V-ing form
could I be expostulating? could you be expostulating? could he be expostulating? could we be expostulating? could you be expostulating? could they be expostulating?
Perfect
could I have expostulated? could you have expostulated? could he have expostulated? could we have expostulated? could you have expostulated? could they have expostulated?
V-ing perfect
could I have been expostulating? could you have been expostulating? could he have been expostulating? could we have been expostulating? could you have been expostulating? could they have been expostulating?
Interro-negative form
Simple form
couldn't I expostulate? couldn't you expostulate? couldn't he expostulate? couldn't we expostulate? couldn't you expostulate? couldn't they expostulate?
V-ing form
couldn't I be expostulating? couldn't you be expostulating? couldn't he be expostulating? couldn't we be expostulating? couldn't you be expostulating? couldn't they be expostulating?
Perfect
couldn't I have expostulated? couldn't you have expostulated? couldn't he have expostulated? couldn't we have expostulated? couldn't you have expostulated? couldn't they have expostulated?
V-ing perfect
couldn't I have been expostulating? couldn't you have been expostulating? couldn't he have been expostulating? couldn't we have been expostulating? couldn't you have been expostulating? couldn't they have been expostulating?